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Light(Science & Applications) 2022年第1期11卷 79-86页

作者： Shuki Enomoto Tomoya Tagami Yusuke Ueda Yuta Moriyama Kentaro Fujiwara Shun takahashi Kenichi Yamashita Faculty of Electrical Engineering and Electronics Kyoto Institute of TechnologyMatsugasakiSakyo-kuKyoto 606-8585Japan

Lead-halide perovskites are highly promising for various optoelectronic applications,including laser devices.However,fundamental photophysics explaining the coherent-light emission from this material system is so intricate and often the subject of debate.Here,we systematically investigate photoluminescence properties of all-inorganic perovskite microcavity at room temperature and discuss the excited state and the light–matter coupling regime depending on excitation density.Angle-resolved photoluminescence clearly exhibits that the microcavity system shows a transition from weak coupling regime to strong coupling regime,revealing the increase in correlated electron–hole pairs.With pumping fluence above the threshold,the photoluminescence signal shows a lasing behavior with bosonic condensation characteristics,accompanied by long-range phase coherence.The excitation density required for the lasing behavior,however,is found to exceed the Mott density,excluding the exciton as the excited state.These results demonstrate that the polaritonic Bardeen–Cooper–Schrieffer state originates the strong coupling formation and the lasing behavior.

关键词： pumping coupling regime

Explainable Analysis of Deep Learning Models for Coronavirus Disease (COVID-19) Classification with Chest X-Ray Images: Towards Practical Applications

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Open Journal of Medical Imaging 2022年第3期12卷 83-102页

作者： Eri Matsuyama Haruyuki Watanabe Noriyuki takahashi Faculty of Informatics University of Fukuchiyama Kyoto Japan School of Radiological Technology Gunma Prefectural College of Health Sciences Gunma Japan School of Hearth Sciences Fukushima Medical University Fukushima Japan

In recent years, with numerous developments of convolutional neural network (CNN) classification models for medical diagnosis, the issue of misrecognition/misclassification has become more and more important. Thus, research on misrecognition/misclassification has been progressing. This study focuses on the problem of misrecognition/misclassification of CNN classification models for coronavirus disease (COVID-19) using chest X-ray images. We construct two models for COVID-19 pneumonia classification by fine-tuning ResNet-50 architecture, i.e., a model retrained with full-sized original images and a model retrained with segmented images. The present study demonstrates the uncertainty (misrecognition/misclassification) of model performance caused by the discrepancy in the shapes of images at the phase of model construction and that of clinical applications. To achieve it, we apply three XAI methods to demonstrate and explain the uncertainty of classification results obtained from the two constructed models assuming for clinical applications. Experimental results indicate that the performance of classification models cannot be maintained when the type of constructed model and the geometric shape of input images are not matched, which may bring about misrecognition in clinical applications. We also notice that the effect of adversarial attack might be induced if the method of image segmentation is not performed properly. The results suggest that the best approach to obtaining a highly reliable prediction in the classification of COVID-19 pneumonia is to construct a model using full-sized original images as training data and use full-sized original images as the input when utilized in clinical applications.

关键词： Explainable AI CNN CXR Image COVID-19 Pneumonia

An international expert consensus of management of recurrent hepatocellular carcinoma: a viewpoint

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Hepatobiliary Surgery and Nutrition 2020年第3期9卷 394-396页

作者： Kuniya Tanaka Yuki takahashi Tetsuji Wakabayashi Department of Gastroenterological and General Surgery Showa University Fujigaoka HospitalYokohamaJapan

We read with great interest the article titled "Multidisciplinary management of recurrent and metastatic hepatocellular carcinoma after resection: an international expert consensus" (1) published in Hepato Biliary Sur... 详细信息

关键词： Surgery hepatocellular carcinoma

Application of Simple Adaptive Control to Water Hydraulic Servo Cylinder System

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Chinese Journal of Mechanical Engineering 2012年第5期25卷 882-888页

作者： ITO Kazuhisa YAMADA Tsuyoshi IKEO Shigeru takahashi Koji College of Systems Engineering and Science Shibaura Institute of Technology Saitama 3378570 Japan Graduate School of Mechanical Engineering Tottori UniversityTottori 6808552 Japan Department of Mechanical Engineering Sophia UniversityTokyo 1028554 Japan

Although conventional model reference adaptive control （MRAC） achieves good tracking performance for cylinder control, the controller structure is much more complicated and has less robustness to disturbance in real applications. This paper discusses the use of simple adaptive control （SAC） for positioning a water hydraulic servo cylinder system. Compared with MRAC, SAC has a simpler and lower order structure, i.e., higher feasibility. The control performance of SAC is examined and evaluated on a water hydraulic servo cylinder system. With the recent increased concerns over global environmental problems, the water hydraulic technique using pure tap water as a pressure medium has become a new drive source comparable to electric, oil hydraulic, and pneumatic drive systems. This technique is also preferred because of its high power density, high safety against fire hazards in production plants, and easy availability. However, the main problems for precise control in a water hydraulic system are steady state errors and overshoot due to its large friction torque and considerable leakage flow. MRAC has been already applied to compensate for these effects, and better control performances have been obtained. However, there have been no reports on the application of SAC for water hydraulics. To make clear the merits of SAC, the tracking control performance and robustness are discussed based on experimental results. SAC is confirmed to give better tracking performance compared with PI control, and a control precision comparable to MRAC （within 10 μm of the reference position） and higher robustness to parameter change, despite the simple controller. The research results ensure a wider application of simple adaptive control in real mechanical systems.

关键词： water hydraulics servo cylinder system positioning control simple adaptive control

Comparison of decompression tubes with metallic stents for the management of right-sided malignant colonic obstruction

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World Journal of Gastroenterology 2019年第16期25卷 1975-1985页

作者： Yoshiyuki Suzuki Konosuke Moritani Yuki Seo Takayuki takahashi Department of Surgery Ashikaga Red Cross HospitalTochigi 326-0843Japan

BACKGROUND Emergency surgical resection is a standard treatment for right-sided malignant colonic obstruction; however, the procedure is associated with high rates of mortality and morbidity. Although a bridge to surgery can be created to obviate the need for emergency surgery, its effects on long-term outcomes and the most practical management strategies for right-sided malignant colonic obstruction remain unclear.AIM To determine the appropriate management approach for right-sided malignant colonic obstruction.METHODS Forty patients with right-sided malignant colonic obstruction who underwent curative resection from January 2007 to April 2017 were included in the study.We compared the perioperative and long-term outcomes of patients who received bridges to surgery established using decompression tubes and those created using self-expandable metallic stents(SEMS). The primary outcome was the overall survival duration(OS) and the secondary endpoints were the diseasefree survival(DFS) duration and the preoperative and postoperative morbidity rates. Analysis was performed on an intention-to-treat basis.RESULTS There were 21 patients in the decompression tube group and 19 in the SEMS group. There were no significant differences in the perioperative morbidity rates of the two groups. The OS rate was significantly higher in the decompression tube group than in the SEMS group(5-year OS rate; decompression tube 79.5%,SEMS 32%, P = 0.043). Multivariate analysis revealed that the bridge to surgery using a decompression tube was significantly associated with the OS(hazard ratio, 17.41; P = 0.004). The 3-year DFS rate was significantly higher in thedecompression tube group than in the SEMS group(68.9% vs 45.9%; log-rank test,P = 0.032). A propensity score–adjusted analysis also demonstrated that the prognosis was significantly better in the decompression tube group than in the SEMS group.CONCLUSION The bridge to surgery using trans-nasal and trans-anal decompression tubes for right-sided malignant colonic obstruction is saf

关键词： Right-sided colon cancer Large bowel obstruction Self-expandable metallic stent Trans-anal tube Trans-nasal tube

Tunable deconfined quantum criticality and interplay of different valence-bond solid phases

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Chinese Physics B 2020年第5期29卷 52-65页

作者：赵博文 Jun takahashi Anders W.Sandvik Department of Physics Boston University590 Commonwealth AvenueBostonMassachusetts 02215USA Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of SciencesBeijing 100190China

We use quantum Monte Carlo simulations to study an S = 1/2 spin model with competing multi-spin interactions. We find a quantum phase transition between a columnar valence-bond solid(cVBS) and a Néel antiferromagnet(AFM), as in the scenario of deconfined quantum-critical points, as well as a transition between the AFM and a staggered valence-bond solid(sVBS). By continuously varying a parameter, the sVBS–AFM and AFM–cVBS boundaries merge into a direct sVBS–cVBS transition. Unlike previous models with putative deconfined AFM–cVBS transitions, e.g., the standard J–Q model,in our extended J–Q model with competing cVBS and sVBS inducing terms the transition can be tuned from continuous to first-order. We find the expected emergent U(1) symmetry of the microscopically Z4 symmetric cVBS order parameter when the transition is continuous. In contrast, when the transition changes to first-order, the clock-like Z4 fluctuations are absent and there is no emergent higher symmetry. We argue that the confined spinons in the sVBS phase are fracton-like.We also present results for an SU(3) symmetric model with a similar phase diagram. The new family of models can serve as a useful tool for further investigating open questions related to deconfined quantum criticality and its associated emergent symmetries.

关键词： quantum phase transitions deconfined quantum criticality quantum spin systems quantum Monte Carlo simulations

COVID-19 pandemic and exacerbation of ulcerative colitis

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World Journal of Clinical Cases 2021年第36期9卷 11220-11227页

作者： Toshikuni Suda Morio takahashi Yasumi Katayama Masaya Tamano Department of Gastroenterology Dokkyo Medical University Saitama Medical CenterKoshigaya 343-8555Japan Department of Gastroenterology Morio ClinicKoshigaya 343-0808Japan

BACKGROUND In 2020,the world faced the unprecedented crisis of coronavirus disease 2019(COVID-19).Besides the infection and its consequences,COVID-19 also resulted in anxiety and stress resulting from severe restrictions on economic and social activities,including for patients with ulcerative colitis(UC).Fresh acute stress exerts stronger influences than continuous stress on UC patients.We therefore hypothesized that the first wave of the COVID-19 pandemic would have serious effects on UC patients and performed this retrospective control study.AIM To determine whether the first wave of the COVID-19 pandemic would have serious effects on UC patients included in a retrospective controlled study.METHODS A total of 289 consecutive UC outpatients seen in March and April 2020 were included in this study.Modified UC disease activity index(UC-DAI)scores on the day of entry and at the previous visit were compared.An increase of≥2 was considered to indicate exacerbation.The exacerbation rate was also compared with that in 256 consecutive control patients independently included in the study from the same period of the previous year in the same manner.RESULTS No significant differences in patient characteristics or pharmacotherapies before entry were seen between the groups.Mean UC-DAI score was significantly higher in subjects during the first wave of COVID-19(0.67+0.07)compared to the previous visit(0.26+0.04;P=0.0000).The exacerbation rate was significantly increased during the first wave of COVID-19,as compared with the previous year(15.9%[46/289]vs 8.9%[23/256];P=0.0151).CONCLUSION This study demonstrated that the COVID-19 pandemic caused exacerbations in UC patients,probably through psychological and physical stress.

关键词： Ulcerative colitis COVID-19 Psychological stress Pharmacotherapy World Health Organization

Comparison of fecal calprotectin levels and endoscopic scores for predicting relapse in patients with ulcerative colitis in remission

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World Journal of Gastroenterology 2023年第47期29卷 6111-6121页

作者： Natsuki Ishida Tatsuhiro Ito Kenichi takahashi Yusuke Asai Takahiro Miyazu Tomohiro Higuchi Satoshi Tamura Shinya Tani Mihoko Yamade Moriya Iwaizumi Yasushi Hamaya Satoshi Osawa Ken Sugimoto Department of Endoscopic and Photodynamic Medicine Hamamatsu University of School of MedicineHamamatsu 431-3192Japan First Department of Medicine Hamamatsu University of School of MedicineHamamatsu 431-3192Japan Department of Laboratory Medicine Hamamatsu University of School of MedicineHamamatsu 431-3192Japan

BACKGROUND Although the usefulness of endoscopic scores,such as the Mayo Endoscopic Subscore(MES),Ulcerative Colitis Endoscopic Index of Severity(UCEIS),and Ulcerative Colitis Colonoscopic Index of Severity(UCCIS),and biomarkers such as fecal calprotectin(FC)for predicting relapse in ulcerative colitis(UC)has been reported,few studies have included endoscopic scores for evaluating the entire colon.AIM To compare the usefulness of FC value and MES,UCEIS,and UCCIS for predicting relapse in patients with UC in clinical remission.METHODS In total,75 patients with UC in clinical and endoscopic remission who visited our institution between February 2019 and March 2022 were enrolled.The diagnosis of UC was confirmed based on the clinical presentation,endoscopic findings,and histology,according to the current established criteria for UC.Fecal samples were collected the day before or after the colonoscopy for measurement of FC.Endoscopic evaluations were performed using MES,UCEIS,and UCCIS.The primary outcome measure of this study was the assessment of the association between relapse within 12 mo and MES,UCEIS,UCCIS,and FC.The secondary outcome was the comparison between endoscopic scores and biomarkers in en-rolled patients with UC with mucosal healing.RESULTSFC and UCCIS showed a significant correlation with UCEIS (r = 0.537, P < 0.001 and r = 0.957, P < 0.001, respectively).Receiver-operating characteristic analysis for predicting MES 0 showed that the area under the curve ofUCCIS was significantly higher than that of FC (P < 0.01). During the 1-year observation period, 18 (24%) patientsexperienced a relapse, and both the FC and UCCIS of the relapse group were significantly higher than that of theremission group. The cut-off values for predicting relapse were set at FC = 323 mg/kg and UCCIS = 10.2. The areaunder the curve of the receiver-operating characteristic analysis for predicting relapse did not show a significantdifference between FC and UCCIS. The accuracy of the endoscopic scores and biomarkers in predicting r

关键词： Ulcerative colitis Mayo Endoscopic Subscore Ulcerative Colitis Endoscopic Index of Severity Ulcerative Colitis Colonoscopic Index of Severity Fecal calprotectin Relapse

Permeability differences based on three-dimensional geometrical information of void spaces

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Journal of Rock Mechanics and Geotechnical Engineering 2021年第2期13卷 368-376页

作者： Dae-Sung Cheon Manabu takahashi Taehyun Kim Geology Division Korea Institute of Geoscience and Mineral ResourcesDaejeonSouth Korea Hydrology Research Group National Institute of Advanced Industrial Science and TechnologyTsukubaJapan Radwaste Disposal Research Division Korea Atomic Energy Research InstituteDaejeonSouth Korea

In this study,the permeabilities of Berea and Otway sandstones were measured under different confining pressures,and porosity was investigated through mercury intrusion porosimetry(MIP).The total porosities of the Berea and Otway sandstones were approximately 17.4%and 25%,respectively.Pore size distributions of each sandstone were almost the same,but the pores in the Otway sandstone were slightly narrower.However,the permeability of the Otway sandstone was smaller than that of the Berea sandstone by one order of magnitude.Three-dimensional(3D)void geometry and geometrical properties of the void spaces relevant to flow were compared to obtain the relation between the permeability differences and porosities of the two sandstones.The 3D geometrical analysis using microfocus X-ray computed tomography(CT)was performed,and the pore geometries of both sandstones were compared using the 3D medial axis(3DMA)method.Pore and throat radii,pore coordination number,tortuosity,number of connecting paths,connecting path volume,and other factors were determined using 3DMA.The Otway sandstone was characterized by a small effective throat/pore radius ratio.Based on the fluid flow mechanism,the lower effective throat/pore radius ratio results in a lower permeability induced by the fluid energy loss,which means that the 3D geometrical shape of void spaces affects the permeability value.

关键词： X-ray computed tomography(CT) Porosity Permeability Geometrical information Three-dimensional medial axis(3DMA)

Synthesis of Highly ordered Large Size Mesoporous Silica and Effect of Stabilization as Enzyme Supports in Organic Solvent

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Chemical Research in Chinese Universities 2002年第2期18卷 200-205页

作者： LI Bo Inagaki S Miyazaki C takahashi H Toyota Central R&D Labs. Inc.411YokomichiNagakute choAichi 4801192Japan

FSM 16, MCM 41 and SBA 15 types of hexagonal mesoporous silica with a highly ordered 2 dimensional structure were synthesized by using different silicon sources and surfactants. In the 2 dimensional silicate framework, pore size can be uniformly controlled by the combined use of the surfactants having different alkyl chain lengths and the swelling agents(triisopropyl benzene). The pore diameter of FSM 16 and MCM 41 can be expanded to be 10 nm, SBA 15 to be 15 nm. The crystal regularity was decreased with the increase of the pore diameter. In FSM 16 derived from kanemite(silicon source) and MCM 41 from water glass, their anionic characteristics on the pore wall may be stronger than those of SBA 15 derived from oligomeric tetramethoxysilane(TMOS). We have successfully used FSM 16 and MCM 41 to immobilize the enzyme having cationic residues below isoelectric point. The level of adsorption of enzymes in FSM 16 and MCM 41 was relatively high, but was low in SBA 15 support. The mechanism of enzyme to be adsorbed in mesoporous silica was suggested to be the ionic interactions. In aqueous solutions, horseradish peroxidase(HTP) was immobilized in FSM 16 with 8.9 nm mesopores and the highest loading amount(183 mg/mg FSM) was obtained, but for the FSM 16 of pore diameter 30 nm only an amount of 28 mg/mg FSM was obtained. The catalytic activity in the organic solvent was high when HRP was immobilized in FSM 16 and MCM 41, but it was low in case of SBA 15.

关键词： Mesoporous silica Surfactant Swelling agent Enzyme Activity